Pressure relief impact absorbing apparatus

ABSTRACT

Pressure relief apparatus comprising means defining a fluidreceiving chamber and having a flexible wall portion consisting of elongated elastic strands which are interwoven whereby adjacent and intersecting strands cooperate to define interstices that are substantially closed when the fluid pressure in the chamber is below the relief pressure. When the fluid pressure in the chamber is raised above the relief pressure the wall portion is flexed outwardly and the strands stretched in proportion to the pressure to open the interstices thereby defining a cumulative fluid relief flow area that is proportionate to the increase in pressure over the relief pressure.

United States Patent Inventor Robert T. Kendall 752 Via Somonte. PalosVerdes Estates. Calif. 90274; Robert S. Tanibata, 16515 Brighton Ave..Gardena, Calif. 90249 Appl No. 18,002 Filed Mar. 11, 1970 Patented Sept.7, 1971 Continuation of application Ser. No. 636,706, May 8, 1967, nowabandoned.

PRESSURE RELIEF IMPACT ABSORBING APPARATUS 10 Claims, 9 Drawing Figs.

[1.8. CI 182/137, 5/347, 137/5 12.15 Int. Cl ..F16k 17/36, A62b 1/22Field of Search 137/560,

References Cited Primary Examiner-William R. Cline Attorney-Fulwider,Patton, Rieber. Lee & Utecht ABSTRACT: Pressure relief apparatuscomprising means defining a fluid-receiving chamber and having aflexible wall portion consisting of elongated elastic strands which areinter woven whereby adjacent and intersecting strands cooperate todefine interstices that are substantially closed when the fluid pressurein the chamber is below the relief pressure. When the fluid pressure inthe chamber is raised above the relief pressure the wall portion isflexed outwardly and the strands stretched in proportion to the pressureto open the interstices thereby defining a cumulative fluid relief flowarea that is proportionate to the increase in pressure over the reliefpressure.

I PRESSURE RELlEF'lMPACT-ABSORBING APPARATUS ROSSREFERENCETO RELATEDAPPLICATION This application "is -a continuation of application 'Ser.No. 636,706;filed May 8, I967, riow bandoned.

BACKGROUND OF THE INVENTION 1 Field of Invention Theprese'ntinventionrelates generally to pressure relief apparatus andmores'pecifically to apparatus which includes a flow area for release offluid, which area increase in size in proportion to increas'esof thepressure being relieved.

2. Description of Prior Art I "Existing pressure relief devicesgenerally include fixed or 'nonexpansibleaperturesfor relief offluid.

SUMMARY OF INVENTION Accordingly, a particular object of the presentinvention is to provide *a'pressu're relief apparatus including meansdefining afluid receiving chamber and having a flexible wallportion"consistingofadjacentelongated members which are interconnectedto'form interstices. The members arepreferably elastic in character tourge the adjacent members together wherebythe intersticesarediminished'in size to restrict fluid flow therethrough. The elasticcharacter of the members further enables them to stretch and bowoutwardly upon an increase influid 'pressu'rein the chamberwhereby theinterstices are enlarged 'in'size in proportion to the increasedpressure whereby flow through "such interstices is correspondinglyincreased. The invention hasparticular'utilityfor use in impactabsorbingpads for relief of internal pressures developed on impact'of a fallitt'gbody upon the (pad, whereby bouncing or rebound of thebodyis'controlled, even to the point of virtual elimination if desired.

Other objects and advantages of the present invention will becomeapparent'from thefollowingdetailed description of a "preferredembodiment thereof, when taken in conjunction with the appendeddrawings.

DESCRIPTIONOFDRAWING S FIG. 1 'is'a perspective view of an impactabsorbing pad accordin g to the .p'reserit'invention;

FIG. 2 isan elevational sectional view taken alongthe lines 2-2'ofFlG.1;

FIG. 3 is a horizontal sectional view taken along the lines 33 of FIG.1;

FIG. 4 is a partial horizontal sectional view taken along the FIG. 5 isa partial front view, in enlarged scale, taken fromthebottom'circle'designated Sin FIG. 1;

FIG. 6 is similar to FIG. 5, but on a more enlarged scale;

FIG. 7 is a side view of a valve according to the present invention;

FIG. 8 is a front view of asecond impact absorbing pad according tothepresent invention; and

FIG. 9 is atop view, on asmallerscale, of the pad shown in FIG. 8.

DESCRIPTION PREFERRED EMBODIMENTS The impact absorbing pad or bodycatcher C includes a bag formed by inpervious square-shaped top andbottom walls 11 and 13, respectively, which are connected together byvertical walls 15 to define afluid-receiving chamber 17. Referring toFIGS. 5 and 6, the vertical walls 15 consist of a material, generallydesignated 19, which is comprised of elongated horizontal and verticalstrands or members 21 and 23, respectively, which are interwoven to forman elastic structure characterized by interstices 25. The elasticity ofthe structure can be a result of the tightly knitted or woven characterthereof, but preferably is provided by making the individual fibers ofan elastic material. The elastic character of the interwoven strands 21and 23 is then effective to normally urge adjacentstrands togetherthereby maintaining the interstices 25 closed, as shown in FIG. 4, andfurther to enable outward flexing of the vertical walls 15 when fluid inthe chamber 17 is 5 pressurized. On pressurization, stretching andoutward bowing designated 31.

To'accomplish the foregoing functions, the top and bottom walls 11 and13-are made of conventional fluid-impervious nylon cloth which ispreferably treated with coatings to pro vide flame resistanceor flameretardance. The elastic fibers forming the peripheral walls 15 areso-called two-way stretch elastic material such as that sold under thetrade name Lycra" by Du Pont De Nemours &'Co., Los Angeles,

California. This material in woven form tends to block or offerrelatively high resistance to a flow of fluid therethrough in itsunstretched or normal condition.

The flexible shaping structure 31 is conveniently made of collapsibleplastic tubing arranged to form top and bottom squares 35 and 37,respectively, which are braced by integral diagonal tubular struts 39.Vertical comer tubes 41 interconnect the top and bottom squares 35 and37 at their respective corners, and vertical side tubes 43 interconnectthe sides of the squares intermediate the corners. A central tube 45interconnects the top and bottom diagonal struts 39 at theirintersections. The hollow interior of the tubular shaping structure 31defines integral and interconnecting pneumatic passages 47*which areinflated through a valve 51 mounted to one side of thetop square 35. Thevalve 51 is preferably a conventional pneumatic tire valve or the like.The catcher C is especially useful for absorbing the impact or kineticenergy of a falling body, such as a person who has jumped or fallen froma considerable height. Operation of the catcher will be described withreference to such exemplary'use. In preparing the catcher C for use theshaping structure 31 is inflated through the valve 51 to a pressuresufficient to cause it to assume the boxlike shape shown in FIG. 1. Thiscan he done orally, but is preferably accomplished through the use of aconventional CO cartridge (not shown) of the type used in inflatingrubber life rafts.

Upon inflation, the top and bottom walls Ill and 13 are spaced-apart andthe vertical walls 15 are distended, thereby forming the chamber 17. Ifdesired, the chamber 17 itself could be pressurized, depending upon thecharacter of the walls 15, that is, their capacity to maintain internalpressures, but in the embodiment shown the chamber 17 is normally atambient pressure.

When the shaping structure 31 is inflated as described ambientair seepsthrough the vertical walls 15 and the chamber 17 will assume atmosphericpressure. When the impacting body strikes the top wall 11, the wall.will flex downwardly, along with the supporting diagonal tubing 39, thusdecreasing the volume of the chamber 17 and thereby tending to increasethe pressure of the contained air and compressing it. Such increase inpressure buckles and bows the vertical walls 15 outwardly and stretchesthe strands 21 and 23, causing the interstices 25 to open and providefor egress therethrough of the contained air.

A particular advantage of the catcher C is that the greater the force ofimpact the greater the increased pressure within the chamber andaccordingly the more the strands 21 and 23 will be stretched thusopening the interstices 25 to a greater extent and allowing egress of aproportionately greater amount of air. Consequently, rather than thekinetic energy absorbed by stopping the impacting body being stored bycompression of the air contained in the chamber 17, and the air thenexpanding rapidly to move the: top wall upwardly and impart an upwardimpulse to the stopped body, this compressed air will at least partiallyescape through the opened interstices 25, thus releasing the absorbedenergy and preventing undesirable bouncing of the body back up to aheight from which the subsequent fall may be injurious unless acontrolled amount of bounce is desired.

When the weight of the stopped body has been removed from the catcher Cthe shaping structure 31 will again distend the top wall 11 andatmospheric air will again seep into the chamber 17, thus preparing thecatcher for another impact.

Referring now to FIG. 8 a second catcher C, embodying the presentinvention, is shown in position for receiving passengers making anemergency exit from the passenger compartment 53 of a passenger airplaneA. It is a particular feature of this catcher C, that it can be elevatedto two selected heights, at lower height for receiving passengers froman airplane that has its wheels up, and a second, higher position, forreceiving passengers from an airplane that has its wheels down.Construction of the catcher C is similar to that of the catcher C exceptthat it is wedge-shaped and constitutes a composite bag, includingindependently distendable upper and lower portions, generally designated55, and 57, respectively.

The lower portion 57 includes a bag formed, in part, by a bottom or basewall 59 and in inclined top wall 61, both of which are made of aconventional fluid-impervious material. The walls 59 and 61 areinterconnected by a pair of triangularshaped opposed sidewalls, one ofwhich is shown at 65, an end d end walls 67 and 69. The sidewalls 65 andend walls 67 and 69 are also made of a material impervious to fluid flowbut obviously could be made entirely or partially of stretch materialsimilar to the above-described material 19 to provide body impactabsorption.

inflatable tubular shaping structure 75, similar to abovedescribedstructure 31, is inflatable to distend the walls 59, 61, 67 and 69 toform a wedge shaped air-receiving compartment similar to compartment 17.Inflation of the structure 75 is through a conventional pneumatic tirevalve or the like (not shown). In addition, the pressurizedair-receiving compartment is preferably independently inflatable throughanother such valve (not shown).

The upper portion 55 of the composite bag or catcher C is shapedsimilarly to portion 57, and includes an inclined fluidimpervious topwall 81, triangular-shaped opposed sidewalls, one being shown at 83, andend walls 87 and 89. The walls 83,

87 and 89 are all made of material like the material 19 previ-' ouslydescribed, and connect the top wall 81 to the top wall 61 of the lowerportion 57.

Inflatable collapsible tubular shaping structure 91, when inflated,distends the walls 81, 83, 87 and 89 away from the wall 61 to form awedge-shaped air-receiving chamber similar to the compartment 17 of thefirst embodiment C.

The tubular shaping structure 91 includes a valve (not shown) similar tovalve 51 for inflating it independently of the structure 75. The variousinflating valves (not shown) may be connected with portable bottles ofcompressed gas whereby the collapsed catcher C can be thrown from theairplane A and inflated automatically from such bottles, or, if desired,orally inflated.

To further enhance the usefulness of the catcher C as a life raft, apair of zippers 92 and 93 (FIG. 9) are provided for detaching the topwall 81 on three sides to open the interior of the catcher for receivingpassengers. The zippers 92 and 93 open from a point 94 intermediate thesidewalls 83 and zip along the end wall 87, turn downwardly along therespective sidewalls 83 thereby leaving the top wall 81 fastened alongthe end wall 89. The intermediate wall 61 is detachable on the samethree sides as the top wall 81 by means of a similar pair of zippers(not shown) which zip along the walls 65 and 67.

in operation, the catcher C can be used to unload passengers from anairplane that has made an emergency wheels-up landing and isconveniently attached to the plane by means of a flap 96. In thissituation, the airplane will be at a lower elevation than that shown inFIG. 8. Therefore, only the bottom portion 57 need have its supportstructure 76 inflated whereby the passengers can jump directly from thepassenger compartment 53 onto the top surface 61 of such portion. On theother hand, when the airplane A has made a wheels-down landing, as shownin FIG. 8, both the upper and lower shaping structures 91 and 75,respectively, are inflated, thereby elevating the impacting surface 81of the top section for receiving passengers jumping from the compartment53. will be clear that with the bottom portion 57 inflated thepassengers jumping onto the inclined surface 61 will be directed awayfrom the airplane A, thus assuring that they will be clear of the exitarea. This same clearing of the exit area is accomplished when both thetop and bottom portions 55 and 57 are inflated and the passengers jumponto the wall 81. Since the walls 59, 61, 65, 67 and 69 of the bottomsection 57 are of a nonporous material the inflated catcher C will floaton water and can be utilized as a life raft when the airplane has madean emergency landing in water. By unzipping the zippers 92 and 93 andfolding back the top wall 81 and also unzipping the zippers attachingthe intermediate wall 61 and folding it back or laying it in the bottomof the catcher, the passengers will be supported directly on the bottomwall 59 thus enhancing the stability of the floating catcher C andproviding weather protection for them by means of the side walls and, ifdesired, by partial closure of the top wall 81.

The pressure relief structure of the catchers C and C is also useful incertain valve applications. For example, and with reference to FIG. 7, avalve V embodying such pressure relief structure is shown connected witha fluid pressure source. More particularly, the valve V includes bodystructure having circular top and bottom walls 95 and 97, respectively,which are connected by a cylindrical wall 99 made of material 19. Thebottom wall 97 includes an inlet which is connected to the pressuresource by a tube 101. When the pressure from the pressure sourceincreases above the relief pressure of the valve V, the material 19 willbe expanded and stretched as described in connection with the catcher Cand will permit rapid egress of the fluid through the open interstices,25, thereby relieving such pressure. Again the cumulative flow ratethrough the interstices 25 will be proportionate to the pressure beingrelieved.

While the above discussion has been directed to a catcher C or reliefvalve V to be utilized for relieving internal pressure, it will be clearthat the present invention is useful for metering pressure into theinternal chamber formed by the body structure and that such type ofoperation is intended to be comprebended.

From the foregoing, it will be apparent that the pressure reliefapparatus of this invention can be conveniently utilized in a bodycatcher C and C that will effectively and efficiently absorb the kineticenergy of the impacting body but which will not induce the body tobounce from the catcher after the impact force has been absorbed.Clearly, if limited bounce were desired, the type of material 19selected would provide for a lesser amount of air escape to correspondwith the desired bounce. The catchers C and C are efficient tomanufacture and use and can be collapsed and easily stored in arelatively small space. They can also be rapidly inflated and readiedfor use and such inflation can be accomplished automatically byconnecting the valves associated with the shaping structure directly toa bottle containing compressed gas. Moreover, the pressure reliefapparatus can be used in valves, such as the valve V, to effectpressureregulation in any of the various systems utilizing fluid underpressure.

Various modifications and changes may be made with regard to theforegoing detailed description without departing from the spirit of theinvention.

lclaim:

1. Pressure relief or metering apparatus for releasing fluid when apredetermined pressure is attained, said apparatus comprising:

a container formed with a fluid-receiving chamber having a flexible wallportion consisting of adjacent elastic members extending in longitudinaland transverse directions, and interconnected to form interstices, theelastic character of said members and the interconnection thereoftending to draw said members together, both longitudinally andtransversely, to maintain said interstices substantially closed when thepressure in said chamber is below said predetermined pressure, theelastic character and interconnection of said members further enablingsaid members to stretch when the fluid pressure increases above saidpredetermined pressure to move adjacent ones of said members apart toopen said interstices and cause them to expand in size in directproportion to said fluid pressure to enable said fluid to escape at arate which increases progressively with the increase of said pressureabove said predetermined pressure.

2. Pressure relief apparatus as set forth in claim 1 wherein:

said flexible wall portion is unconstrained to enable it to expand inoverall area and cause said elastic members to diminish in cross sectionas they are stretched to thereby enhance the enlargement of saidinterstices to increase the rate of discharge of said fluid.

3. Pressure relief or metering apparatus as set forth in claim 1wherein:

said elastic members are interconnected by weaving to enable saidrespective longitudinal and transversemembers to shift with respect toone another:

4. Energy-absorbing apparatus for absorbing the energy of an impactingbody of a predetermined weight and comprising:

a flexible container for interposition between said body and animpacting surface, said container being formed with a fluid chamber ofsufficient size to receive a predetermined volume of a selected fluid,said chamber including a flexible wall portion consisting of adjacentelongated flexible members interconnected to form interstices, saidinterstices in the normal state of said members being diminished in sizeto restrict fluid flow therethrough and the flexible character of saidelongated members being sufflcient to cause said interstices to beenlarged sufficiently, by the pressure differential across said wallportion resulting from said impacting body flexing the walls of saidcontainer and reducing the volume of said chamber, to meter said fluidthrough the enlarged interstices at a rate sufficient to enable saidcontainer to gradually collapse and absorb the kinetic energy of saidbody. 5. Energy-absorbing apparatus as set forth in claim 4 thatincludes:

flexible shaping structures for normally urging said container to anuncollapsed configuration and sufficiently flexible to be collapsed bythe impact of said body. 6. Energy-absorbing apparatus as set forth inclaim 5 wherein:

said flexible shaping structure is formed by fluid inflatablecollapsible tubing. 7. Energy-absorbing apparatus as set forth in claim4 wherein:

said elongated members are of sufficiently flexible character to enablesaid interstices to become sufficiently enlarged by said pressureincrease to provide absorption of substantially all of said kineticenergy of said impacting body whereby there is substantially no reboundof said body. 8. Energy-absorbing apparatus as set forth in claim 4wherein:

said container is formed with a base wall and an oppositely disposedimpacting wall. 9. Energy-absorbing apparatus as set forth in claim 8wherein:

said base wall and impacting wall are relatively airtight and saidimpacting wall is sloped relative to said base wall. 10.Energy-absorbing apparatus as set forth in claim 4 that includes:

an inflatable container disposed beneath said flexible container forelevating it.

1. Pressure relief or metering apparatus for releasing fluid when apredetermined pressure is attained, said apparatus comprising: acontainer formed with a fluid-receiving chamber having a flexible wallportion consisting of adjacent elastic members extending in longitudinaland transverse directions, and interconnected to form interstices, theelastic character of said members and the interconnection thereoftending to draw said members together, both longitudinally andtransversely, to maintain said interstices substantially closed when thepressure in said chamber is below said predetermined pressure, theelastic character and interconnection of said members further enablingsaid members to stretch when the fluid pressure increases above saidpredetermined pressure to move adjacent ones of said members apart toopen said interstices and cause them to expand in size in directproportion to said fluid pressure to enable said fluid to escape at arate which increases progressively with the increase of said pressureabove said predetermined pressure.
 2. Pressure relief apparatus as setforth in claim 1 wherein: said flexible wall portion is unconstrained toenable it to expand in overall area and cause said elastic members todiminish in cross section as they are stretched to thereby enhance theenlargement of said interstices to increase the rate of discharge ofsaid fluid.
 3. Pressure relief or metering apparatus as set forth inclaim 1 wherein: said elastic members are interconnected by weaving toenable said respective longitudinal and transverse members to shift withrespect to one another.
 4. Energy-absorbing apparatus for absorbing theenergy of an impacting body of a predetermined weight and comprising: aflexible container for interposition between said body and an impactingsurface, said container being formed with a fluid chamber of sufficientsize to receive a predetermined volume of a selected fluid, said chamberincluding a flexible wall portion consisting of adjacent elongatedflexible members interconnected to form interstices, said interstices inthe normal state of said members being diminished in size to restrictfluid flow therethrough and the flexible character of said elongatedmembers being sufficient to cause said interstices to be enlargedsufficiently, by the pressure differential across said wall portionresulting from said impacting body flexing the walls of said containerand reducing the volume of said chamber, to meter said fluid through theenlarged interstices at a rate sufficient to enable said container togradually collapse and absorb the kinetic energy of said body. 5.ENergy-absorbing apparatus as set forth in claim 4 that includes:flexible shaping structures for normally urging said container to anuncollapsed configuration and sufficiently flexible to be collapsed bythe impact of said body.
 6. Energy-absorbing apparatus as set forth inclaim 5 wherein: said flexible shaping structure is formed by fluidinflatable collapsible tubing.
 7. Energy-absorbing apparatus as setforth in claim 4 wherein: said elongated members are of sufficientlyflexible character to enable said interstices to become sufficientlyenlarged by said pressure increase to provide absorption ofsubstantially all of said kinetic energy of said impacting body wherebythere is substantially no rebound of said body.
 8. Energy-absorbingapparatus as set forth in claim 4 wherein: said container is formed witha base wall and an oppositely disposed impacting wall. 9.Energy-absorbing apparatus as set forth in claim 8 wherein: said basewall and impacting wall are relatively airtight and said impacting wallis sloped relative to said base wall.
 10. Energy-absorbing apparatus asset forth in claim 4 that includes: an inflatable container disposedbeneath said flexible container for elevating it.